No space after number for metric units?

I recently failed a Gengo standard test. One of the criticisms I received was that metric units should be placed adjacent to the number. After much research online, I found that the majority, if not all, depictions of metric units have a space after the number.

Which method is correct? I was unable to find the specific information regarding it on this site.

"The International System of Units (SI) recommends inserting a space between a number and a unit of measurement units and between units in compound units, but never between a prefix and a base unit.

5.0 cm not 5.0cm or 5.0 c m45 kg not 45kg or 45 k g32 °C not 32°C or 32° C20 kN m not 20 kNm or 20 k Nm50 % not 50% (Note: % is not an SI unit, and many style guides do not follow this recommendation)The only exception to this rule in the SI the symbolic notation of angles: degree (e.g. 30°), minute of arc (e.g. 22′), and second of arc (e.g. 8″)." - http://en.wikipedia.org/wiki/Space_(punctuation)#Spaces_and_unit_symbols

AP style doesn't put a space. Basically, whatever the style guide says is what goes- which means a decision needs to be made about the style guide *here* (if the client doesn't provide his/her own house style guide)